A method of manufacturing a solar cell for solar light power generation is as follows. First, after preparing a substrate, a rear electrode layer is formed on the substrate and patterned by a laser, thereby forming a plurality of rear electrodes.
Then, an optical absorption layer, a buffer layer, and a high resistance buffer layer are sequentially formed on the rear electrodes. The optical absorption layer can be formed by extensively using various schemes including a scheme of forming a Cu(In,Ga)Se2 (CIGS) based-optical absorption layer by simultaneously or separately evaporating Cu, In, Ga, and Se and a scheme of performing a selenization process after a metallic precursor film has been formed.
Then, the buffer layer including cadmium sulfide (CdS) is formed on the optical absorption layer through the sputtering process.
Next, groove patterns may be formed in the optical absorption layer, the buffer layer, and the high resistance buffer layer.
Then, a transparent conductive material is deposited on the high resistance buffer layer and the transparent conductive material is filled in the groove pattern. Thus, a transparent electrode layer is formed on the high resistance buffer layer and connection wires are formed inside the groove patterns, respectively.
After that, the groove pattern is formed in the transparent electrode layer, thereby forming a plurality of solar cells. The transparent electrodes and the high-resistance buffers correspond to cells, respectively. The transparent electrodes and the high-resistance buffers may be arranged in the form of a stripe or a matrix.
The transparent electrodes are misaligned with the rear electrodes and the transparent electrodes are electrically connected with the rear electrodes through the connection wires. Therefore, a plurality of solar cells can be electrically connected with each other in series.
Meanwhile, according to the related art, the rear electrode layer is divided into a plurality of rear electrodes by patterning the rear electrode layer and the optical absorption layer, the buffer layer and the front electrode layer are deposited on the rear electrodes to manufacture the solar cell.
However, the deposition process for the optical absorption layer is carried out at the high temperature of 500° C. or above, so the support substrate may be bent while the deposition process for the optical absorption layer is being carried out. Such a bending of the support substrate may exert an influence upon the rear electrode layer so that the pattern formed in the rear electrode layer may also be bent. Due to the bending phenomenon, a non-generation region, that is, a dead zone area is increased in the solar cell so that the efficiency of the solar cell may be deteriorated.
Therefore, there are required to provide a solar cell having a new structure capable of preventing a support substrate from being bent and a method for manufacturing the same.